New report by US scientists exposes irrelevance of GM mouse research
Does a mouse effectively represent you in medical research? After decades of genetics research on mice, that has always assumed a specific gene in a mouse is the same as the equivalent gene in a person, scientists are now beginning to realise that the genes often don�t match up.
This assumed match is the basis for a huge amount of research using many millions of genetically modified (GM) mice. Scientists select a human gene of interest, then �knock out� its equivalent in a mouse to see what happens, and thereby, they say, ascertain the function of the gene in people.
But researchers from the University of Michigan in the USA have recently published work revealing that this entire assumption is wrong. They took 120 genes that are absolutely essential to survival and reproduction in humans and looked at data where the genes had been knocked out in mice so that they couldn�t function. If the 120 genes involved were equivalent in humans and mice, the knockout mice would have died or at least been unable to reproduce.
However, they discovered that 22% of the so called �essential genes� in humans weren�t essential in mice. This shows that identical genes behave differently in mice and humans and throws further serious doubt on the whole basis for GM mouse research.
So what�s the alternative? The Dr Hadwen Trust has long suspected that equivalent genes in humans and mice don�t have the same effect, and last year we had a special call to find projects that replace GM mice in research.
One very promising grant that arose from this is being conducted by researchers at the University of York. This project involves �knocking out� genes in donated human tissues in the laboratory. The researchers take donated human tissue such as bone marrow and extract a special type of cell called mesenchymal stem cells. These cells have the ability to turn into many different types of cell in the test-tube including bone, cartilage and fat cells.
The researchers then knock out specific genes in the mesenchymal stem cells before growing them into 3-D structures of the selected cell type. This allows the scientists to see the effects of the gene knockout in human tissues, so there�s no need to worry about species differences. Vital work like this can provide the type of alternative approaches that are essential if animals are to be replaced in the laboratory, and has the potential to save countless animals� lives.